Not exactly. According to a 2013 study published in New England Journal of Medicine, the average guy who weighs 150 pounds burns around 3.5 calories per minute of sex. And according to a 2008 Penn State survey of sex therapists, satisfying sex lasts between three and 13 minutes—that’s less than 50 calories burned per session on a good day.

Nobody has sex to lose weight or build muscle in the first place, but there are definitely some things you can to do up the ante in the bedroom. For example, studies have shown that merely anticipating sex triggers an influx of testosterone into your system. Because elevated testosterone levels increase calorie burn, extended foreplay will help maximize your sex workout, says competitive powerlifter Robert Herbst.

Sex isn’t going to replace leg day, but it can definitely be a healthy part of your active lifestyle, says sex therapist Kat Van Kirk, author of The Married Sex Solution. “Plenty of sex positions engage your core,” Van Kirk says. “Or can be modified to be more of a workout, if not the workout.”

Missionary is usually a pretty low-key position, but Van Kirk says you can take a moment to do some isometric work. And it’s pretty simple — though you’ll have an easier time if you’re on a harder mattress: When you’re on top, hold yourself up in a plank position and let her come to you.

Any position in which you’re supporting some or all of her weight (as well as your own) is going to be a better workout than when you’re, well, not. The wheelbarrow position is sort of a modified doggy style: She puts her hands on the floor and you stand behind her, lifting her legs up and holding her ankles (her legs will be bent) so you can penetrate her from behind. And if you’re looking for something a little more challenging, you can adjust the angle of the wheelbarrow by getting into a squat position, Van Kirk says.

You might think sex in water would be easier, but it’s actually harder, Van Kirk says. “Because there’s no friction in water, you’ll use a lot of energy and strength simply staying in position,” she explains. Almost any position will work, but remember to use lube—water washes away her natural lubricant and it could become uncomfortable.

Perhaps the best way to guarantee sex is a workout is to support all of her body weight while standing, Van Kirk says. The position is simple: You stand, and she wraps her arms around your neck. You pick her up and penetrate her while she wraps her legs around your waist (hook your elbows under her knees for more lift). This position engages your entire core, as well as your neck and arms, and it can be modified by leaning her back against a wall.

This girl-on-top position is not for the faint of heart or the inflexible. For this position, you will need to get into the reverse table or upward bow and hold your position. She can then lower herself onto you, supporting some or all of her weight with her feet as she rides you. Try not to do this on a concrete floor.